Adjustable rack



FIG. 1 is a perspective view of an adjustable rack;

FIG. 2 is a front side plan view thereof;

FIG. 3 is a rear side plan view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a right side view thereof, with the left side being substantially the same thereto. 

I claim the ornamental design for an adjustable rack, as shown and described. 